Piston



J. B. LARGER June 5, 1934.

flsmon Filed Sept. '28. 1932 2 Sheets-Sheet 1 I I l VUVMWP Inventor j/wra 0 792" June 5, 1934. B ARGER 1,961,886

PISTON Filed Sept. 28; 1932 2 Sheets-Sheet 2 Inventor Q if I Ja I Attorney Patented June 5, v V l i f v A "UNITED STATES, PATENT OFFICE John B. Larger, Louisville, Ky., assignor of onehali. to Frank Larger, Louisville, Ky., and one.- half to Jerome E. Bartel, Cincinnati, Ohio Application September 28, 1932, Serial No. 635,268 3 Claims. (01. 309-10) This invention relates to pistons for internal 12 and journalled to the wrist pin is the upper end combustion engines. of the connecting rod 13. The lower end of the It is the aim of the invention to construct a connecting rod 13 is adapted for connection to piston that translatesthe maximum amount of the crank of the crank shaft not shown, but. the power to the crank shaft of an internal combusrevolution of the crank is denoted by the broken so tion enginewith a minimum wear on the cylinder line 14 in Figure 1 of the drawings. wall, thereby obviating the customary necessity The piston A consists of a hollow cylindrical of resurfacing the cylinder walls. body portion of the customary shape and has a Another feature of the invention is to make crown portion 18, and integral head 19, ,a skirt the operation of the motor comparatively quiet portion 15, and a wrist pin 11 between the crown 65 I by overcoming what I believe to be the cause of and skirt portions.

the Piston knocks p va g in the Conventional The piston A is formed with a round skirt 15 the int rnal combust o ine. 4 surface of which is substantially tangent -to the It is a fairly Well established feet that the walls of the cylinders 10 except for the usual 15 piston knocks of internal combustion engines clearance used in all current practice. On one 70 results from the tendency f h pi n to r segment there is formed in the skirt an inverted 0n the axis of h Wrist D From y Observa- V-shaped slot indicated generally at 16. The tion I believe that th f r ul rocking m v m mouth of this slot is at the lower edge of the skirt that causes knocks an x iv w occurs y 15 and the width of the slot at the mouth is subon t power stroke and this tendency to o stantially the length of the wrist pin 11. The 7 Occurs in One direction, that is, clockwise sides of the slot 16 slopes uniformly to the apex with sp c t t a of the w st pi By 1'1 which is on a plane with the bottom of the. modifying the Piston crown and skirt to allow wrist pin 11, and the edges of the'sides are flat great freedom to rock, Within reasonable or square. The slot 16 is at right angles to the its Which I deem to b Within a range between a axis of the wrist pin 11 and in vertical alinement g0 th ty Sec and SiXty fourth Of an inch ever with the greatest clearance in the crown as will the Cus m y Practice, the excessiveiwear and hereinafter more fully appear. Slot 16 forms knocking noise is eliminated o a marked degree a relieved area in the skirt which has the corol- In the draw g wherein the Purpose Of lary advantage of reducing friction with the cylillustration is Shown the Preferred embodiment inder wall with the attendant reduction of wear- 85 0f the i v like refereneeschal'aeters indiing surface and increased lubrication to the parts Ca like p t throughout the Several Views of the piston where there is the most friction. Where The crown 18 of the piston is formed with the Figure 1 is a vertical detailed section through a customary peripheral piston ring grooves and cylinder Of an internal Combustion engine ShOW- piston ring flanges indicated generally at B so I ing the piston in accordance the present in- C respectively and four grooves are preferred Ventien in elevationthis invention. The grooves B receive the con- Figure 2 is an enlarged fragmentary Sectlon of ventional piston rings R. All of the flanges prior a cylinder Showing the piston elevation to my modification have the customary clearance 40 Figure 3 is a View Similar to Figure 2 n taken accepted by the general practice in the art. It 95 at ht angles th is therefore pointed out that the flanges that are Figure is detailed Vertlal e untreated by my invention conform to the usual piston taken substantially on line 44 of Figure 3. practice with regard to c1earance Fi ure 5 is a horizontal section token 011 line In the head of the piston I form a circular cavof Figure ity 19 having a diameter substantially the same 0 Figure 5 is an enlarged fragmentary elevatlon as the width of the hollow interior of the piston or the P and and of a preferred depth to the plane of the upper Figure 7 is a diagrammatic view illustrating the edge of t first to ring groove. v Above the clearance in the c ow of the p n. cavity is a flat perpendicular shoulder 20, the In the drawings, 10 indicates the walls of the purpose of which is to disperse the reactionary 105 cylinder of an internal combustion engine and forces and products of combustion away from the said walls are circular in cross section. Slidably cylinder walls. It is my belief that I retain a mountedin the cylinderis apiston A- constructed larger percentage of the power of each power in accordance with the present invention. In stroke from the cavity inithe head. the pistonisthe'wristpin 11 mountedinbearlngs To overcome the contact of the top of the no crown of the piston with the cylinder wall caused by the rocking of the piston on the power stroke I modify the two upper piston ring flanges indicated generally at 21 and 22. Beginning at points indicated by the dotted lines 23, 24 the faces of both these flanges 21 and 22 in the segments denoted by the dotted lines D and E are relieved or cut away, or ground away, to provide greaten clearance. The are described between the lines 23 and 24 indicated at F is unmodified and conforms to the original radius. The faces of flanges 21 and 22 are relieved, cut away or ground away in a true segment, the radius of which is considerably greater than the original radius which provides the greatest clearance at right angles to the axis of the wrist pin 11.

The axis of the wrist pin is in the direction of the dotted lines 23, 24. From the point of greatest clearance the faces of the flanges taper outwardly and uniformly along the increased radius to a substantial tangency with the original radius at the lines 23, 24 where the relieved segments D and E merge with the arc F. The are F is on the wrist pin axis. The clearance for the segments D and E on the first piston ring flange 21 is greater than the corresponding segments on the second piston ring flange 22 thereby making steps to the third or unmodified piston ring flange C.

By reason of the foregoing construction the piston of this invention is allowed a greater rocking movement, on the axis of the wrist pin. The slot 16 is provided in the skirt of the piston t6 compensate for the rocking of the crown since the apex 17 of the slot is located in vertical alinement with the greatest clearance in the flanges and at right angles to the axis of the wrist pin. Moreover, the tendency to rock the piston in a clock-( wise direction with respect to Figure 1 which latter view furnishes a clear understanding of the position of the slot 16 with respect to the clearance of the piston ring flanges 21 and 22. It is believed that the relieved area D in the crown,

the slot or relieved area 16, in conjunction with the piston rings R eliminate the knock on the power stroke. The reason for the relieved area E on the same side of the crown as the slot 16, is to remove any tendency of the'piston to knock on the up-stroke when the piston rocks back gradually to normal position.

Having thus described my invention, what I claim is:

menses 1. A piston comprising a crown, a skirt, and wrist pin bearings, the skirt being smooth and formed with a relieved segment at the lower end thereof, said crown formed with plural piston ring grooves, a piston ring in each groove, the flanges of the piston ring grooves at the uppermost portion of the crown being relieved in segments allowing the balance of the lowermost flanges to remain unaltered with respect to the conven tional cylinder clearance, and said relieved segments in the crown and 'skirt being located on the opposite side of a vertical plane passing through the axis of the wrist pin bearings whereby the said relieved portions and rings cooperate to eliminate piston knock resulting from rocking of the piston about the wrist pin as an axis.

2. A piston comprising a crown, a skirt, and

wrist pin bearings intermediate the crown and skirt, said skirt formed with an inverted V-shaped slot in its lower end. said crown formed with plural piston ring grooves, rings in said grooves, the flanges of the uppermost grooves being relieved in segments less than the semi-circumference of the piston leaving the lowermost flanges of the grooves unaltered with respect to the conventional cylinder clearance, and said slot and relieved segments of the flanges being located on the opposite sides of a vertical plane passing through the axis of the wrist pin bearings whereby the said slot, relieved portions and rings cooperate to eliminate piston knock resulting from rocking of the piston about the wrist pin as an axis.

3. 'A piston comprising a rigid crown, skirt, and wrist pin bearings, said wrist pin bearings lying intermediate the crown and skirt, said skirt formed with an inverted V-shaped slot in its lower edge, said crown formed with plural piston ring grooves, rings in said grooves, the flanges of the uppermost grooves being relieved in segments less than a semi-circumference of the piston leaving the lowermost flanges of the grooves unaltered with respect to the conventional cylinder clearance, said segmental relieved portions of the flanges being located on the opposite sides of the axis of the wrist pin bearings, and said slot located diametrically opposite certain of the relieved flange segments whereby the said relieved portions, slot and rings cooperate to eliminate piston knock resulting from rocking of the piston about the wrist pin as an axis.

JOHN B. LARGER. 

